Investment machine for making shell molds



April 15, 1958 J. A. SHELBY ETAL 2,830,337

- INVESTMENT MACHINE FOR MAKING SHELL MOLDS Filed July 1, 1954 4Sheets-Sheet 1 12 J 20 17 1 I/n tons:

' e/afin @4. Jkezz Mllan F Paton April 15, 1958 J. A. SHELBY L 2,830,337

INVESTMENT MACHINE FOR MAKING SHELL MOLDS Filed July 1, 1954 4Sheets-Sheet 5 17 13 J5 wib'fi .14 1 1 i I i m lfl L I g; E 1 5 April15, 1958 J. A. SHELBY E L 2,830,337

INVESTMENT MACHINE FOR MAKING SHELL MOLDS Filed July 1, 1954 ,4Sheets-Sheet 4 LL I @fllan I'Pazou United States Patent generally heatedand a sand and suitable binder mixture is delivered to the heatedpatternwhereupon a relatively thin frangible shell is formed. This shellis suitably cured by heating or bakingand during the casting operation apair of complementary shells are placed together in assembly whereuponcasting material is poured into the cavity provided by the shell-typemolds. Various devices for investing the pattern with the binder sandmixture have .been devised. Most of these devices have performedsatisfactorily but they have not been designed for high production ofshell molds. It is a prime object of this invention therefore to providean improved investment machine for manufacturing shell-type molds on aproduction basis. i

It is still a further object of this invention to provide an improvedinvestment apparatus adapted to be placed adjacent a plurality ofconveyors which deliver a pattern to the investment machine whereuponthe pattern is covered with a sand binder mixture while it is in aheated condition and whereupon it is discharged to one of the conveyorsfor conveyance to a baking oven for suitably curing the shell mold.

Still another object is to provide an improvement in a shell moldinvestment apparatus the improvement including means for releasablylocking a pattern carrier on the platform of an investment machine, thecarrier being locked during investing of the pattern with a sand mixture"whereupon the locking means is releasable for releasing the patterncarrier so that it can be delivered to suitable conveying means adjacentthe apparatus.

A still further object of the invention is to provide improved means forinvesting the heated pattern witha sand binder mixture including adevice for rotating the pattern to an inverted position for dischargingexcess investment material from the pattern.

These and further objects will become more readily apparent from areading of the specification in connection with the accompanying sheetsof drawings.

In the drawings:

Figure 1 is a side view, in elevation, of an improved investmentapparatus for manufacturing shell-type molds;

Figure 2 is a front view, in elevation, of the apparatus shown in Figure1;

Figure 3 is an elevational view showing a portion of an investmentmachine taken substantially along the line 33 of Figure 1;

Figure 4 is a cross-sectional view taken substantially along the line 44of Figure l;

Figure 5 is a cross-sectional view through the investment apparatustaken substantially along the lines 5-5 of Figure 2; and,

Figure 6 is a sectional view similar to Figure 5 showing one operatingposition in the operating cycle of the investment apparatus. A

An investment machine is generally designated by the reference character10. The machine 10 comprises a supporting structure 11 consisting ofupright members 12 ,gate 51 is connected to a pivot pin 52 pivotallyconnected 2,830,337 Patented Apr. 15, 1958 :track rollers 13. The trackrollers 13, which are positioned on the front upright members 12, aresuitably journ-alled on a shaft 14 which is carried in bearing members15. The track rollers 13 which are carried on the rear upright members12 are suitably journalled on stub shafts 17 in turn journalled inbearing supports 18. Each roller 13 of the rear upright members 12 issupported on two bearing supports 18 one of which is'suitably supportedon an upright member 19 as best indicated in Figure 3. The front andrear uprights 12 are securely connected together by means of ahorizontally extending beam 20. In addition the uprights 12 are suitablyconnected by means of.

supporting members 21 extending laterally relative to the beams 20.

The supporting structure 11 supports a rotatable frame 22. The rotatableframe 22 comprises a pair of laterally spaced and parallel circulartrack members 23. The track members 23 are connected at their forwardportions by means of a lateral brace 24 and are suitably connected atrear portions by means of upper and lower channel beams 25.

A platform is provided on a rotatable frame 22, this platform includingchannel members 26 and 27 positioned in parallel relation as best shownin Figure 4. The channels 26 and 27 are suitably connected to beams 28,which as best shown in Figure 2, are connected to the track members 23by means of angle members 29. A plurality of conveyor rollers 30 aresuitably pivotally connected to the channels 26 and 27 to provide aroller conveyor.

The rotatable frame 22 also supports a plurality of longitudinallyextending, or normally upright, track frame members 31. The uprighttrack members 31 have each suitably connectedthereto parallel verticallyextending upright rods 32 defining a suitable vertically extending track.means. A bracket structure generally designated at 33 is best shown inFigures 4, 5 and 6. The bracket structure 33 includes side plates 34suitably connected by means of a an end plate 35 which is also connectedto a bottom plate 36. A plurality of rollers 37 are suitably journalledon the side plates 34, the rollers 37 being positioned to roll 1 on thetracks formed by the upright rods 32. A pair of laterally spaced andparallel T-beams 3S suitably support an investment material drum orhopper generally designated by the reference character 39.

The drum or hopper 39 comprises a circular housing 40 having an inletopening 41 and an outlet opening 42. An arcuate closure gate 43 ispositioned within the drum 39 for suitably opening and closing theoutlet 42. A pair of laterally spaced track members 44 are positionedimmediately adjacent the outlet opening 42. The track members 44 serveto provide guides for the arcuate closure gate 43. A pair of arms 45 areconnected to the :gate 43, these arms being rigidly connected to a shaft46. As best shown in Figure 4 a shaft 46 is pivoted on the drum 39 andis connected to a crank arm 47 which in turn is connected to a pistonarm 48. The piston arm 48 is reciprocably positioned within a cylinderor fluid extensible device 49 which is pivotally connected, as indicatedat 50, in Figure 4, to one of the T-beams 38.

An inletclosure gate 51 is positioned over the inlet opening 41 as bestshown in Figures 5 and 6. The closure to the drum 39, the said pin 52,in turn being connected 1 to an arm 53 adapted to rotate the closuregate 51 on the said pivot pin 52. The arm 53 is connected to a pistonrod 54 reciprocably positioned within a fluid extensible device 55. Theextensible device 55 is connected asindicated at 56 to the drum 39.

in Figure underneath the chute extension 61.

3 As best shown in Figures 1 and 5 a'supply chute 57 is positioned abovethe inlet opening 41. The supply chute 57 includes a valve member 58adapted to suitably control the discharge ofmaterial from the chute 57by means of a fluid extensible device 59. The chute or hood 60 isconnected to the material drum 39, and an extension 61 in turn connectedto the chute 60. The drum 39 is closed chamber within the extension 61in the chute 60.

adapted to be vertically moved on the upright trackmembers 31 by meansof a piston rod 62 which is connected to the channel bottom member orplate 36. The piston rod62 in turn is reciproc'ably positioned withrespect tora fiuid extensible device 63suita'bly positioned on a rollers30. A pattern support 67 is mounted on the carrier 65and in turnsupports a pattern 68. As best shown in Figures 2, 5 and 6, the carrier65 is provided with oppositelydisposed access openings 69. A stripperplate'70 is vertically movable within the carrier 65 and is maintainedtherein by means of substantially parallel' angle supports 71 suitablyconnected to the carrier 65.

Means for maintaining thecarrier 65 within theinvestment machine 10 isprovided in the form of releasable holders generally designated at 72.The releasable holders 72 are suitably supported by means of brackets'73on angle members 74 connected to beams 28 (bestshown One of thereleasable holders 72 is positioned on opposite sides of the patterncarrier 65. Each holder172 includesa laterally extending shaft 75 whichis mounted for rotation on the brackets 73. A crank arm 76 is attachedto each shaft 75 the crank arm being mov- -able by a piston 77 on afiuid extensible cylinder 78." As

best shown in Figures 2 and 5, ears 80 extend upwardly from the angle 74these ears also supporting the shaft 75. A finger 81 is connected toeach laterally extending shaft 75, the fingers extending through theopenings 69 as, best shown in Figures 5 and 6. The fingers 81 areadapted to engage the upper edge of the stripper plate 70' and tomaintain the same in lowered relation relative to the angle 71. This inefifect locks the carrier 65 in position for the investment operation.

A pair of pulleys 82are connected for rotation with a shaft 83 which issuitably journalled on bearingmem- -bers 84 suitably supported on thetransversely spaced horizontal beams 20. A pair of cables 85 are woundaroundthe pulleys 82 and are connected to the circular goperation thecarrier 65, which contains the pattern 68, is delivered to the conveyorrollers 30. At this stage of the operation, the apparatus is in theposition'shown in Figures 1 and 2, the carrier has moved into positionand the extensible devices 78 are effective to rotate the shaft 75 insuch a manner that the fingers 81 engage the upper edge of thestripperplate 70 to securely maintain the pattern carrier and pattern 65 inposition immediately As indicated" in Figure 1, the drum 39 is in afilling position with reference to. the supply chute 57. The inletclosure gate 51 is opened during the upward movement. of the drum '39and the valve 58 is effective to permit the discharge of a resin bindermixture to the interior of the drum" 40.

Material is now delivered tofthe drum. until it reaches a-level positionimmediately below thc lowerm'ost: point of-the chute 57. The drum 39 isthen lowered relative --to the chute 57 and the inlet closurev gate 51closesto :suitably close the inlet opening of the drum. The drum isino'w mo'ved downwardly until the extension 61- completely isurrounds'thepattern and provides in 'e'ffect a The gate 43, which has been closeduntil this time, is now opened by means of cylinder 49. Material fromthe drum now drops down upon the pattern 68. The pattern 68 has beenheated and the material consisting primarily 'of a binder and sandmixture forms a thin layer on top of the heated pattern 68. After thepattern 68 has been invested with the material it is desired toimmediately. remove. the excess from the pattern and return the same tothe drum 39. At this point the rotating frame 22 is rotated by means ofthe cables (and a suitable power unit not shown which is connected tothe shaft 83) thereby causing the units mounted thereon to rotate to theposition shown in Figure 6. In this position the closure gate 43 of thedrum is open and any excess sand and binder mixture which is placed onthe pattern is returned by gravity to the drum. The gate 43 now closesand the rotatable frame 22 returns to its normal position shown inFigure 5 whereupon the drum 39 can again be moved upwardly in fillingposition with respect to the supply chute 57. The release holders 72arenow released so that the carrier can be moved from the rollers 30 toone of the adjacent conveyors (not shown) which will deliver the carrierand pattern to a suitable curing oven.

T o summarize the operation it can be stated that the drum moves up'intoposition for receiving a binder sand mixture from the chute 57.Thereupon the drum is lowered until the extension 61 is disposedinsubstantially sealed relation around the pattern 68. The gate 43 isnow opened and material descends onto the pattern 68 whereupon thepattern frame and pattern are rotated so that any excess sand isreturned. tothe drum. After return of the excess material to the drumthe outlet gate is again closed and the drum is moved to its fillingposition. The releasable holders are released so that the carrier candepart from the conveyor rollers 30 to another conveyor for delivery tothe curing oven.

The apparatus shown can easily produce, on a large quantity basis, shellmolds as the patterns are-delivered from the preheating oven. The unitcan be quickly rotated to a position where any excess binder sandmixture is returned to the hopper. By the novel arrangement shown, apattern carrier may be utilized, the pattern carrier being suitable tosupport the pattern in position during variousoperations before andafter it has been placed in the investment machine. By suitablyconnecting the device to a switch control unit, complete automaticoperation can readily be procured. Thus it can be seen that the objectsof the invention have been fully achieved and that a mass productionshell mold investment apparatus has been provided. It must be understoodthat changes may be made in the invention without departing from thespirit of the invention or the scope thereof as defined in the appendedclaims.

What is claimed is:

1. An investment machine for investing a pattern with a mold. materialcomprising; a supporting structure, a

plurality of bearing rollers mounted on said supporting opening, aplatform, carried by said frame, conveyor meanson said platform, apattern carrier movable on said conveyor to a position beneath saidhood, said carrier comprising a box frame having a stripperplate'enclosed 'thereinfor relative reciprocating movement relative totensible means adapted to engage said stripper plate for locking saidcarrier in position on said conveyor, second fluid pressure extensiblemeans connected to said frame and to'said bracket for moving said drumto a position whereby said chute extends through said inletopening 'forsupplying material to said drum, said second extensible means beingadapted to move said drum to a second position whereby said hood is inengagement with said carrier over a pattern carried therein and saiddrum is moved away from said chute, means connected to said inletclosure gate for closing the same in the second position of said drum,means connected to said outlet closure gate for opening said gate duringthe second position of said drum whereby material within said drum isdeposited on the pattern, and means for rotating said frame with thedrum in said second position whereby excess material l on the pattern isreturned to said drum by gravity.

' 2. An investment machine for investing a pattern with a mold material,comprising; a supporting structure, a rotatable frame including a pairoflaterally spaced and aligned circular track members, said track membersbeing 'rotatably supported on said supporting structure, a pair oflongitudinally extending track members mounted on said frame, a bracketmovably mounted on said longitudinal track members, a drum supported onsaid bracket,

. said drum having an inlet opening and an outlet opening, I an inletclosure gate for said inlet opening, an outlet .closure gate for saidoutlet opening, a hood connected to said drum and in communication withsaid outlet opening, a supply chute positioned above said inlet opening,a platform carried by said frame, conveyor means on said platform, apattern carrier movable on said conveyor vto a position beneath saidhood, said carr er comprising a box frame having a stripper plateenclosed therein for relative reciprocating movement relative to apattern .carried on said carrier, first fluid pressure extensible meansadapted to engage said stripper plate for locking said carrier inposition on said conveyor, second fluid pressure extensible meansconnected to said frame and to said bracket for moving said drum to aposition where- -by said chute extends through said inlet opening forsupplying material to said drum, said second extensible means beingadapted to move said drum to a second position whereby said hood is inengagement with said carrier over a pattern carried therein and saiddrum is moved away from said chute, means connected to said inletclosure gate for closing the same in the second position of said drum,means connected to said outlet closure gate for opening said gate duringthe second position of said drum whereby material within said drum isdeposited on the pattern, and means for rotating said frame with thedrum in said second position whereby excess material on the pattern isreturned to said drum by gravity.

3. An investment machine for investing a pattern with .a mold material,comprising; a supporting structure, a

rotatable frame including a pair of first track members, said firsttrack members being supported for rotation on said support, a pair ofsecond track members mounted ;on said frame, a' drum supported on saidsecond track members, said drum having an inlet opening and an outletopening, an inlet closure gate for said inlet opening, an outlet closuregate for said outlet opening, a hood connected to said drum and incommunication with said outlet opening, a supply chute positioned abovesaid inlet opening, a platform carried by said frame, a pattern carrieron said platform beneath said hood, said carrier being adapted tosupporta pattern, first fluid pressure extensible means adapted to engage saidcarrier for locking said carrier in position on said platform, secondfluid pressure extensible means connected to said frame for moving saiddrum to a position whereby said chute extends through said inlet openingfor supplying material to said drum, said second extensible means beingadapted,

nected to said inlet closure gate for closing the same in the secondposition of said drum, means connected to said outlet closure gate foropening said gate during the second position of said drum and materialwithin said drum is deposited on the pattern, and means for rotatingsaid frame with the drum in said second position whereby excess materialon the pattern is returned to said drum by gravity.

4'. An investment 'machine for investing a pattern with a mold material,comprising; a supporting structure, a rotatable frame including a pairof laterally spaced first track members, said first track members beingrotatably supported on said supporting structure, a pair of second trackmembers mounted on said frame, a bracket movably mounted on said secondtrack members, a drum supported on said bracket, said drum having aninlet opening and an outlet opening, an inlet closure gate for'said'inlet opening, an outlet closure gate for said outlet p to saidbracket for moving said drum to a position whereby said chute extendsthrough said inlet opening for supplying material to said drum, saidsecond extensible means being adapted to move said drum to a secondposition whereby said hood is over a pattern carried on said carrier,means connected to said inlet closure gate for closing the same in thesecond position of said drum, means connected to said outlet closuregate for opening said gate during the second position of said drumwhereby material within said drum is deposited on the pattern, and meansfor rotating said frame with the drum in said second position wherebyexcess material on the pattern is returned to said drum by gravity.

5. An investment machine for investing a pattern with a mold material,comprising; a supporting structure, a frame rotatably supported on saidsupporting structure, a pair of track members mounted on said frame, adrum supported on said track members, said drum having an inlet openingand an outlet opening, a hood connected to said drum and incommunication with said outlet opening, a supply chute positioned abovesaid inlet opening, a platform carried by said frame, a pattern carrieron said platform beneath said hood, said carrier being adapted tocarry apattern below said hool, first fluid pressure extensible means adaptedto engage said carrier for locking said carrier in position on saidplatform,'second fluid pressure extensible means connected to said framefor moving said drum to a position whereby said chute extends throughsaid inlet opening for supplying material to said drum, said secondextensible means being adapted to move said drum to a second positionwhereby said on the pattern is returned to said drum by gravity.

6. An investment machine for investing a pattern with a mold material,comprising; a supporting structure, a frame supported on said support, adrum supported on said frame, said drum having an inlet opening and anoutlet opening, a hood connected to said drum and in 7 communicationwith said' outlet opening, a supply chute positioned above said inletopening, a platform carried by said frame, conveyor means on saidplatform, a pattern carrier movable on said conveyor to a positionbeneath said hood, said carrier being adapted to support a patternbeneath said hood, means for locking said carrier in posipattern, andmeans for moving said frame with the drum in said second positionwhereby excess material on the pattern is returned to said drum bygravity.

7. An investment machine for investing a pattern with a mold material,comprising; a supporting structure, a frame rotatably supported on saidsupport, a drum supported on said frame, said drum having an inletopening and an outlet opening-a hood connected to said drum and incommunicationwith said outlet opening, a supply chute positioned abovesaid inlet opening, a platform carried by. said frame, a pattern carriersupported on said platform beneath said hood, said ,carrier beingadapted to support apattern beneath said; hood,

first actuating means connected to saidframe' for moving said drum to aposition whereby said chute extends through said inlet opening forsupplying material to said drum, said first actuating means beingadapted to move said drum to a second position whereby said hood ispositioned over a pattern carried on said carrier, means connected tosaid inletopening for closing the same in the second position of saiddrum, means connected to said outlet opening for opening the same duringthe second position of saiddrum whereby material within said drum isdeposited onthe pattern, and second actuating means for rotating saidframe with the drum insaid second position whereby excess material onthe:pattern is returned to said drum'by gravity.

8. An apparatus for investing a pattern with a mold material comprising;a support, a frame including a pair of circular track members rotatablycarried by saidsupport, a conveyor carried by said frame, a pattern.carrier supported on said conveyor, said carrier having a patternsupported thereon, a second frame supported on said first frame, a drumon said second frame, said drum having aninlet opening and an outletopening, a supplychute positioned in proximityto. said inlet opening, ahood connected to said drum and adapted to communicate with said outletopening, actuating means connected to said second frame for raising thesame and said drum on the track members into a first position wherebysaid chute extends through said inlet opening into said drum, saidactuating means being adapted to move said:drum to a second positionremotefrom saidchute whereby said outlet opening and hood is disposedover said pattern and material is directed through said outlet openingover said pattern, inlet closure means adapted to-close said inletopening during the second position, means to open said outlet openingduring said second position, and means connected to said first frame forrotating the same relative to said support whereby excess material onsaid pattern returns by gravity to said drum through said outletOpening.

9. An apparatus for investing a pattern with a mold material comprising;a support, a frame including apair of circular track members rotatablycarried said support; a conveyor carried by said frame, a patterncarrier supported on said conveyor, said carrier having a patternsupported thereon, a second'frame supported onsaid first frame, a drumonsaid second frame said drum having an inlet opening and an outletopening, asupply I chute positioned in proximity to said inletopening,.actuatingmeans connected to said second'frame for moving thesame andsaid drum on thetrack members into a first position whereby saidchute extends through said inlet openinginto said drum, said actuatingmeans being adapted to move said drum to a second position remote fromsaid chute whereby said outlet opening is disposed over said pattern andmaterial is directed through said outlet opening over said pattern,inlet closuremeans adapted to close said inlet opening during the secondposition,-means to open said outlet opening during said second position,and means connected to said first frame for rotating the same relativeto said support whereby excess material on said pattern returns bygravity to a said drum through said outlet opening.

10. An apparatus for investing a pattern with a mold materialcomprising; a support, a frame including a pair of circular trackmembers carried by said support, a platform carried by said frame forrotation about a horizontal axis, a pattern carrier supported on saidplatform, said carrier having a pattern supported thereon, a secondframe supported on said first frame, a drum on said second frame, saiddrum having an inlet opening and an outlet opening, a supply chutepositioned in proximity to'said inlet opening, actuating means connectedto said second frame for moving the same and said drum" onthe trackmembers into a first position whereby said chute extends through saidinlet opening into said drum, said actuating means being adapted to movesaid drum to a second position remote from said chute whereby saidoutletopening is disposed over said pattern and material is directedthrough said outlet opening over said pattern, inlet closure -meansadapted to close said inlet opening during the'secend position, means toopen said outlet opening during said second position, and meansconnected to saidfirst frame for rotating the same relative to'saidsupport whereby excess material on said pattern returns by gravity tosaid drum through said outlet opening.

11. An apparatus for investing a pattern with amold material comprising;a, support, a frame carried bysaid support for rotation about ahorizontal axis, a conveyor carried by said frame, a pattern carriersupported on said conveyor, said carrier having a pattern supportedthereon, a second fame supported on said first-frame, a drum on saidsecond frame, said drum having an inlet openingand an outlet opening, asupply chute positioned in proximity to said inlet opening, a hoodconnected to saiddrum and adapted to communicate with said outletopening,actuating means connected to said second frame for raising'thesame and said drum into a first position whereby said chute extendsthrough said inlet opening into saiddrum, said actuation meansbeingadapted to move said drum to a second position remote from said chutewhereby said hood is disposed over said pattern and material is directedthrough said outlet opening over said pattern, inlet closure meansadapted to close said inlet opening during the second positiom-means toopen said outlet opening 3 References Cited in the file of this patentUNITED STATES PATENTS 2,317,574 Williams Apr. 27,-1943 2,659,944 ValyiNov. 24, 1953 2,724,158 Davis et al Nov. 22,1955

OTHER REFERENCES Foundry,'November. 1952, page 265. Fortune, July 1952,pages 104-106, and 143.

